It is known to administer drugs transdermally i.e. by maintaining a drug in intimate contact with a patient's skin so that the active constituent slowly passes through the skin and is absorbed into the patient's body over a prolonged period of time.
The drug is usually held in position for the requisite period of time using an adhesive patch, the drug being incorporated as an integral part of the patch for example by admixture with the adhesive. However, the problem arises that such patches can be inconvenient or difficult to manufacture especially where mass-production of different patches containing different drugs is required.